Emulsified fat spreads, in particular margarines, desirably provide certain consumer benefits, usually in terms of the taste properties. One important consumer benefit of a spread is its mouth texture. Factors which contribute to mouth texture are cooling impact, mouthmelt, and mouthfeel (cleanup). A preferred emulsified spread provides a significant cooling impact, a rapid, sharp melt sensation, and no coated or waxy feel on the tongue. Another important consumer benefit is the temperature cycling stability of the spread. During normal usage, spreads such as margarines are repeatedly taken in and out of the refrigerator and are thus exposed to a frequent cycle of warmer and colder temperatures. Also, during storage and shipment, the spread can be subjected to warmer and colder temperatures. Such temperature cycling can affect the properties of the spread, especially mouth texture. Preferred emulsified spreads have temperature cycling stability, i.e. the ability to be taken in and out of the refrigerator without significant adverse effects.
The spread should also satisfy certain consumer requirements in terms of the handling properties. The spread should be sufficiently plastic to be easily spread on soft foods such as bread or toast. Another important consumer requirement is heat stability or resistance to slump. The spread should not lose its shape (slump) upon exposure to room temperatures while the spread is used. Preferred emulsified spreads will maximize the benefits of mouth texture and temperature cycling stability while at the same time satisfying the consumer requirements for spreadability and heat stability.
The emulsified spread normally used as the yardstick for all others, especially with regard to mouth texture, is butter. Butter has a particularly pleasing mouth texture. The cooling impact on the tongue is significant and the mouthmelt is rapid and sharp with no coated or waxy mouthfeel. The heat stability of butter is also adequate. However, refrigerated butter can become quite hard, and therefore difficult to spread, especially after temperature cycling.
To improve the spreadability of the emulsified spread while approximatizing the mouth texture of butter, workers in the art have developed various margarines in stick and tub-type forms. Perhaps most important to the spreadability and mouth texture of a margarine is the margarine fat used. These margarine fats usually contain a sufficient solids content to provide heat stability to the margarine at room temperature yet have sufficient plasticity to be spreadable when refrigerated. Such fats often contain a soft oil high in polyunsaturated fatty acids (linoleic and linolenic) such as safflower oil or sunflower oil. Blends of fats and oils are frequently used in formulating such margarine fats.
One category of margarine fat contains triglycerides high in lauric acid content, such as coconut oil, palm kernel oil and babassu oil. These triglyceride compositions are brittle at refrigerator temperatures and have such low melting points (coconut oil melts at 75.degree. F. (24.degree. C.) to 80.degree. F. (26.6.degree. C.)) such that the spreadability and heat stability of the margarine formed therefrom can be affected. See Bailey's Industrial Oil and Fat Products (3rd ed. 1964), p. 339. Improvements in the spreadability and heat stability of margarines made from high lauric acid content fats are achieved by appropriate blending with other fats and oils and interesterification. See U.S. Pat. No. 2,874,056 to Drew, issued Feb. 17, 1959 (margarine fat containing coconut-type oil, glycerides of higher fatty acids of coconut oil and glycerides of caprylic-capric-caproic acids); U.S. Pat. No. 3,006,771 to Babayan, issued Oct. 31, 1961 (margarine fat containing coconut-type oil modified with one or more triglycerides having fatty acids of from 6 to 10 carbon atoms which can be further interesterified with triglycerides having fatty acids of from 16 to 18 carbon atoms); U.S. Pat. No. 3,949,105 to Wieske et al, issued Apr. 6, 1976 (margarine fat containing interesterified blend of coconut oil, palm oil and hydrogenated oil). See also U.S. Pat. No. 3,592,661 to Seiden, issued July 13, 1971 (margarine fat containing interesterified trilaurin and tripalmitin).
Margarine fats can also be made from triglycerides which have predominantly long chain length fatty acids (e.g. palmitic, stearic, oleic and/or linoleic acid residues). These long chain fatty acid triglycerides can be interesterified to provide margarine fats having different melting profiles. See for example, U.S. Pat. No. Re. 30,086 to Carlisle et al, issued Aug. 28, 1979 (margarine fat consisting essentially of randomized palm oil); U.S. Pat. No. 3,889,011 to Read, issued June 10, 1975 (margarine fat containing palm oil or cottonseed oil co-randomized with soybean or sunflower oil); U.S. Pat. No. 3,634,100 to Fondu et al, issued Jan. 11, 1972 (margarine fat containing liquid oil such as sunflower or safflower oil, and co-randomized blend of coconut oil, palm oil and palm stearine); U.S. Pat. No. 3,859,447 to Sreenivasan, issued Jan. 7, 1975 (margarine fat containing oils high in linoleic acid content such as sunflower oil and safflower oil which have been interesterified). More typically, the long chain fatty acid triglyceride is a hydrogenated (hardened) oil. See Bailey's Industrial Oil and Fat Products, supra, at page 339. Hydrogenation increases the solids content of the oil which raises the melting point of the margarine fat, thus increasing the heat stability of margarine. Other methods for increasing the heat stability of the margarine have also been practiced. See U.S. Pat. No. 3,956,522 to Kattenberg et al, issued May 11, 1976 (margarine fat high in polyunsaturated fatty acid content containing hydrogenated hardstock fat from which higher melting triglycerides have been removed by fractionation).
Most commercial margarines are sufficiently plastic when refrigerated to have satisfactory spreadability properties and have sufficient solids content to provide heat stability at normal room temperatures. However, commercial margarines, especially those formulated from margarine fats containing hydrogenated oils, have mouthmelting properties which are flat or "thick" in character with a waxy or coated mouthfeel. Also, the temperature impact on the tongue does not provide a cooling sensation close to that of butter. Thus, while commercial margarines satisfy consumer requirements for spreadability and heat stability, they lack the mouth texture of butter.
Single fractionated or "topped" palm oil fats have been used in formulating margarine products to improve mouth texture. U.S. Pat. No. 3,189,465 to Oakley et al, issued June 15, 1965 relates to a "cool tasting" margarine wherein at least a major proportion of the fat phase consists of one or more lower melting fractions. These lower melting fractions can be obtained from semi-soft fats by single thermal fractionation in which the higher melting fraction containing substantially all the trisaturated glycerides is removed. A representative example of such a fat phase consists of about 60 to 70% topped palm oil, about 15 to 25% lard (whole or topped), with the remaining fat being ground nut oil. Margarines formulated with topped palm oil, such as the liquid fraction from a single thermal fraction of palm oil, do not satisfy the consumer requirements for heat stability in a stick-type product. Also, margarines made from topped palm oil are extremely brittle and difficult to spread. See also U.S. Pat. No. 4,055,679 to Kattenberg et al, issued Oct. 25, 1977 (plastic fat suitable for margarines containing a palm-based fat such as palm olein co-randomized with fats such as soybean oil or safflower oil); U.S. Pat. No. 4,087,564 to Poot et al, issued May 2, 1978 (olein fraction obtained by single thermal fraction of co-randomized blend of palm oil and soybean oil).
Double fractionated palm oil fats are also known in the art but are used as cocoa butter substitutes and extenders. One example is disclosed in U.S. Pat. No. 4,205,095 to Pike et al, issued May 27, 1980, which relates to a thermal fraction method for producing a palm mid-fraction suitable as a cocoa butter substitute or extender. Refined, bleached palm oil is heated (70.degree.-75.degree. C.) and then immediately cooled (28.degree.-33.degree. C.) to form a first liquid fraction (iodine value 55-60) and a first solid fraction (iodine value 38-44 and melting point 50.degree.-55.degree. C.). The first liquid fraction is separated, heated (60.degree.-65.degree. C.) and then immediately cooled (14.degree.-17.degree. C.) to produce a second liquid fraction (iodine value 59-64) and the desired palm mid-fraction (iodine value 48-53 and melting point 32.degree.-36.degree. C.) which is disclosed as having about 83% by weight symmetrical mono-unsaturated triglycerides and asymmetrical di-unsaturated triglycerides combined. The palm mid-fraction is separated and then hydrogenated to an iodine value of 38-45 to provide a hydrogenated palm mid-fraction having a melting point of 33.degree.-36.degree. C.
Another such example is disclosed in British Patent Specification 827,172 to Best et al, published Feb. 3, 1960, which relates to a method for making a cocoa butter substitute by a two-step solvent fractionation of palm oil. The palm mid-fraction used as the cocoa butter substitute has an iodine value of up to about 45 (preferably 30-36) and a softening point of 30.degree.-45.degree. C. (preferably 32.degree.-37.degree. C.). This desired palm mid-fraction can be obtained by removing 5 to 15% of a high melting glyceride fraction containing fully saturated triglycerides and at least 50% (preferably 60%) by weight of a low melting glyceride fraction. British Patent Specifications 1,431,781 to Padley et al, published Apr. 14, 1976, and 1,390,936 to Soetters et al, published Apr. 16, 1975, which blend such solvent fractionated palm mid-fractions with other fats to form cocoa butter extenders disclose one such palm mid-fraction having 3.1% trisaturated triglycerides, 76.5% symmetrical mono-unsaturated triglycerides, 7.1% asymmetrical mono-unsaturated triglycerides and 8.3% asymmetrical di-unsaturated triglycerides, with an iodine value of about 34 and a melting point of about 33.degree. C. See also British Patent Specification 893,337 to Dansk Sojakagefabrik), published Apr. 4, 1962 (bloom inhibiting fat mixtures (melting range 31.degree.-43.degree. C.) containing at least 65% mono-unsaturated triglycerides obtained from double solvent fractionated shea butter and palm oil); U.S. Pat. No. 3,012,891 to Best et al, issued Dec. 12, 1961 (cocoa butter substitute formed from blend of double solvent fractionated palm mid-fraction and double solvent fractionated shea butter mid-fraction); U.S. Pat. No. 2,903,363 to Farr, issued Sept. 8, 1959 (cocoa butter-like fat having at least 75% mono-unsaturated triglycerides obtained by double solvent fractionation of palm oil); U.S. Pat. No. 3,686,240 to Kawada et al, issued Aug. 22, 1972, (cocoa butter substitute having a melting point of 33.degree.-38.degree. C. formed from a hydrogenated palm mid-fraction (iodine value of 38-47 and melting point of 27.degree.-31.degree. C.) obtained from double solvent fractionated palm oil).
It is an object of the present invention to provide a fat suitable as a structural fat for margarines or other emulsified spreads which imparts a desirable mouth texture and temperature cycling stability.
It is another object of the present invention to provide a fat suitable as a structural fat for margarines and other emulsified spreads which imparts satisfactory spreadability and heat stability, especially to stick-type products.
It is another object of the present invention to provide a fat suitable as a structural fat for margarines and other emulsified spreads which imparts improved consumer benefits of mouth texture and temperature cycling stability while at the same time satisfying consumer requirements for spreadability and heat stability.
It is yet a further object of the present invention to provide a fat suitable as a structural fat for margarines and other emulsified spreads which can be obtained from double fractionated palm oil.
These and further objects of the present application are hereinafter disclosed.